Chapter 3 Pathology Questions

Chapter 3 Review Questions 1. What is meant by the following shapes Homologous chromo several(prenominal)s- A matched pair of chromosomes, ace derived from each p bent. twain members of the pair are similar in surface, shape, and appearance, except for sex chromosomes. Autosomes- The general term for chromosomes other than the sex chromosomes. Sex chromosome- The X and Y chromosomes that determine genetic sex. Barr body- The inactivated X chromosome that appears as a pocketable, dense crowd of chromatin attached to the nuclear tissue layer of somatic cubicles.This structure can be identified in the cells of a prevalent female and is c on the wholeed a sex chromatin body or Barr body subsequently the man who first described it. Gene- are segments of DNA chains that determine some property of the cell and are the base units of inheritance. Sometimes, they are described as being arranged along the chromosome like bead on a string. Gametogenesis- A specialize type of cell division that occurs during the teaching of the ball (ova) and sperm. The development of mature eggs and sperm from forerunner cells.Centrosome- A small region of cytoplasm adjacent to the magnetic core that contains the centrioles and serves to organize microtubules. 2. How does the process of mitosis compare with myosis? In mitosis, each of the two sore cells (called the daughter cells) resulting from the cell division sop ups the same(p) subprogram of chromosomes that were move over in the trumpeter cell (called the rise cell). In meiosis, the number of chromosomes is reduced so that the daughter cells receive only half of the chromosomes possessed by the parent cell. This process is not undefiled until fertilized by the sperm. . What are the differences between spermatogenesis and oogenesis? First, tetrad spermatozoa are produced from each precursor cell in spermatogenesis, but only angiotensin converting enzyme ovum is formed from each precursor cell in oogenesis. The other troika daughter cells derived from the meiotic divisions are cast a focal point as polar bodies. Second, spermatogenesis occurs continually and is carried through and through to complation in about 2 months. Consequently, seminal fluid always contains sexual intercoursely wise sperm. In contrast, the oocytes are not produced continually.All of the oocytes present in the ovary were formed before short letter and halt remained in a protract prophase of the first meiotic division from foetal life until they are ovulated. 4. What is a chromosome karyotype? How is it obtained? How is it employ? A chromosome karyotype is an arrangement of chromosomes from a wizard cell arrangement in pairs in descending order according to size of the chromosomes and the positions of the centromeres. A chromosome karyotype is obtained by culturing cells in a suitable medium. Usually, human blood is apply as a source of cells for these studies the blood lymphocytes can be induced to bear mitotic division.Certain chemicals are added to stop the mitotic division after(prenominal) the chromosomes have become separate and distinct, and accordingly , many cells arrested in mitosis accumulate in the culture medium. Additional methods are busy to cause swelling of the cells, which are and so prepared, and the chromosomes can be examined. The chromosomes are wherefore arranged according to their size, the location of the centromere, the relative lengths of the chromatids that extend outward from the centromere, and the pattern of open-eyed and dark bands along the chromosomes.Then the separated chromosome from unmatchable cell are photographed and arranged into a karyotype. The presence of abnormalities in chromosome number or structure can be find this way. 5. What is the MHC? What is its function? What is its relationship to disease efficiency? The MHC is the major histocompatibility complex. The antigens present on cells are persistent by a gang of genes on chromosome 6. This group of genes, which was first determined in laboratory animals in association with ingraftation experiments, is called the MHC.Originally, MHC proteins were considered of interest only with evaluate to organ transplantation because transplantation of cells containing MHC proteins antithetical from those of the transplant recipient was followed by rejection of the transplant unless the immune outline was suppressed. They take opus in generating immune responses to foreign antigens of all types. The interaction of the HLA antigens with the various cells of the immune system is considered in the discussion on immunity, hypersensitivity, allergy, and autoimmune diseases. 6.What is a haplotype? How are haplotypes inherited by children from their parents? What are the chances that two children will have the same haplotype? A haplotype is a make up of HLA genes on one chromosome and is transmitted as a unit. Each child receives one of two possible haplotypes from each parent. Because of the way in which chromosomes are transmitted from parent to child, the child has any of quaternion opposite combinations of HLA haplotypes. There is one in four probability that two children will both(prenominal) possess the same pair of HLA haplotypes.